This invention relates to new silicic acid heteropolycondensates, to a process for their production and to their use as coating compositions, particularly in the culture of living cells.
Tissue and cell cultures are used for histological cytological, molecular-biological and similar studies, generally being prepared beforehand in suitable nutrient media. Living cells of higher organisms, for example liver cells, are also increasingly being used for pharmacological studies. In this way, it is possible to obtain more relevant test results, i.e. test results which provide a clearer reflection of the actual physiological conditions in the living organisms, than by conventional biochemical test methods. For example, enzyme activity is frequently related to the physiological conditions of a functioning living cell and the active co-operation of the cell wall is necessary for numerous biochemical and biological processes. These in vitro methods using living cell cultures are suitable for example for testing medicaments and for developing specific indicators for cell and ecological poisons.
The culture of living cells often requires special conditions. For example, cells emanating from body tissue have to be grown on mechanical supports which enable the cells to grow within the structure or in close proximity thereto. The use of conventional supports, for example glasses or plastics, involves the problem that the cells show poor adhesion to the support and become detached during culture in nutrient solutions so that the requirement of growth within the structure is not satisfied. This phenomenon is particularly pronounced in cases where highly dilute serums are used as the nutrient solutions.
It has now been found that certain silicic acid heteropolycondensates are particularly suitable for use as coatings on standard support materials, for example glass vessels, for solving the problem stated above, i.e. they provide excellent supports for the preparation of tissue and cell cultures. The cells are firmly bound to the support, presumably through chemical binding forces, so that growth within the cell structure is guaranteed. In addition, the silicic acid heteropolycondensates according to the invention are suitable for various other technical applications.